Osmosis — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

8 What is meant by osmosis? A The diffusion of water molecules from a region of their higher concentration to a region of their lower concentration as a result of their random movement. B The diffusion of water molecules from a region of their higher concentration to a region of their lower concentration through a partially permeable membrane. C The diffusion of water molecules from a region of their lower concentration to a region of their higher concentration as a result of their random movement. D The diffusion of water molecules from a region of their lower concentration to a region of their higher concentration through a partially permeable membrane.

1 marks

Answer: B

This question in 0654/21 May/June 2017

10 In plants, water is absorbed from the soil into root hair cells. Why does this occur? A The concentration of salts is higher in the soil than inside the cells. B The concentration of water is lower in the soil than inside the cells. C The water potential of the soil is higher than inside the cells. D The water potential of the soil is lower than inside the cells.

1 marks

Answer: C

This question in 0654/22 May/June 2017

11 What is osmosis? A the diffusion of sugar molecules from a concentrated solution to a dilute solution through a partially permeable membrane B the diffusion of sugar molecules from a dilute solution to a concentrated solution through a partially permeable membrane C the diffusion of water molecules from a concentrated solution to a dilute solution through a partially permeable membrane D the diffusion of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane

1 marks

Answer: D

This question in 0654/21 Oct/Nov 2017

4 Plant cells are placed in a solution with a water potential higher than the cells. Which row is correct? movement of water volume of vacuole A enters cells decreases B enters cells increases C leaves cells decreases D leaves cells increases

1 marks

Answer: B

This question in 0654/22 Oct/Nov 2018

2 The diagram shows a red blood cell. If it is placed in water, it will burst. If a plant cell is placed in water, it will not burst. What prevents a plant cell from bursting? A cell wall B nucleus C regular shape D vacuole

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2018

2 When a plant cell is put into a solution which has a lower water potential than the cell, the cytoplasm can pull away from the cell wall. What is the term for this? A flaccid B plasmolysis C turgid D turgor pressure

1 marks

Answer: B

This question in 0654/22 May/June 2019

2 The diagram shows a cell starting to plasmolyse. X Y Z In which direction is osmosis occurring? A X to Y B Y to X C Y to Z D Z to Y

1 marks

Answer: D

This question in 0654/23 May/June 2019

2 Pieces of potato (a plant) of the same size were placed in sucrose solutions of different concentrations. Their length was measured after two hours. At which sucrose concentration were the pieces most flaccid? + change 0 in length concentration of sucrose solution – A B C D

1 marks

Answer: D

This question in 0654/23 May/June 2020

2 Which cell is most flaccid? A B C D

1 marks

Answer: C

This question in 0654/22 May/June 2021

2 What is an example of osmosis? A a dried out piece of leaf stalk swelling up when placed in a bowl of water B carbon dioxide entering a leaf when it is photosynthesising C red blood cells travelling to the lungs to collect oxygen D the passage of digested food molecules through the wall of the small intestine

1 marks

Answer: A

This question in 0654/23 Oct/Nov 2021

2 The diagram shows a cell starting to plasmolyse. X Y Z In which direction is osmosis occurring? A X to Y B Y to X C Y to Z D Z to Y

1 marks

Answer: D

This question in 0654/22 Feb/March 2022

2 Red onion cells are placed in distilled water. Which statement is correct? A The cells plasmolyse; water moves into the cells from a high to a low water potential. B The cells plasmolyse; water moves out of the cells from a low to a high water potential. C The cells become turgid; water moves into the cells from a high to a low water potential. D The cells become turgid; water moves out of the cells from a low to a high water potential.

1 marks

Answer: C

This question in 0654/21 Oct/Nov 2022

2 The photograph shows red onion cells placed in a concentrated salt solution. Which statement explains their appearance? A Water has moved into the cells against a water potential gradient. B Water has moved out of the cells down a water potential gradient. C Water has moved out of the cells against a water potential gradient. D Water has moved into the cells down a water potential gradient.

1 marks

Answer: B

This question in 0654/23 Oct/Nov 2022

2 Which description for the process of osmosis is correct? A Osmosis is the movement of water molecules from a region of high water potential across a fully permeable membrane to a region of lower water potential. B Osmosis is the movement of water molecules from a region of low water potential across a partially permeable membrane to a region of high water potential. C Osmosis is the movement of water molecules from a region of high water potential across a partially permeable membrane to a region of lower water potential. D Osmosis is the movement of water molecules from a region of low water potential across a fully permeable membrane to a region of high water potential.

1 marks

Answer: C

This question in 0654/22 Feb/March 2023

2 What is meant by osmosis? A the net movement of water molecules from a region of higher water potential to a region of lower water potential through a cell wall B the net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane C the net movement of water molecules from a region of lower water potential to a region of higher water potential through a cell wall D the net movement of water molecules from a region of lower water potential to a region of higher water potential through a partially permeable membrane

1 marks

Answer: B

This question in 0654/21 May/June 2023

2 When a plant cell is put into a solution that has a lower water potential than the cell, the cytoplasm can pull away from the cell wall. What is the term for this? A flaccid B plasmolysis C turgid D turgor pressure

1 marks

Answer: B

This question in 0654/21 Oct/Nov 2023

2 What is osmosis? A the diffusion of sugar molecules from a concentrated solution to a dilute solution through a partially permeable membrane B the diffusion of sugar molecules from a dilute solution to a concentrated solution through a partially permeable membrane C the diffusion of water molecules from a concentrated solution to a dilute solution through a partially permeable membrane D the diffusion of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane

1 marks

Answer: D

This question in 0654/22 Oct/Nov 2023

2 Pieces of potato of the same length were placed in sucrose solutions of different concentrations. Their length was measured again after two hours. At which sucrose concentration were the pieces of potato most flaccid? + change 0 in length concentration of sucrose solution – A B C D

1 marks

Answer: D

This question in 0654/23 Oct/Nov 2024

2 A salmon is a fish that can live in both fresh and salt water. Salmon are affected by water movement when the environment changes. Which diagram shows the internal and external water potential and the movement of water when a salmon is in fresh water? A B low water low water potential potential high water high water potential potential C D high water high water potential potential low water low water potential potential

1 marks

Answer: D

This question in 0654/22 Feb/March 2025

3 The mass of a peeled potato is recorded. The potato is put in a salt solution with a lower water potential than the potato for two hours. The outside of the potato is then dried and the mass recorded. Which statement explains what happens to the potato after two hours in the salt solution? A It gained mass by osmosis as salt moved into the potato from the surrounding solution. B It gained mass by osmosis as water moved into the potato from the surrounding solution. C It lost mass by osmosis as water moved from the potato into the surrounding solution. D It lost mass by osmosis as salt moved from the potato into the surrounding solution.

1 marks

Answer: C

This question in 0654/22 May/June 2025

2 The mass of a potato cylinder is recorded. The potato cylinder is then placed into concentrated sucrose solution. After 2 hours, the potato cylinder is removed from the solution and the mass recorded. The results are shown. time / hours mass / g 0 2.50 2 1.65 Which statement explains the change in mass of the potato? A Sucrose moves out of the potato cells because the solution has a higher water potential than the cells. B Sucrose moves out of the potato cells because the solution has a lower water potential than the cells. C Water moves out of the potato cells because the solution has a higher water potential than the cells. D Water moves out of the potato cells because the solution has a lower water potential than the cells.

1 marks

Answer: D

This question in 0654/22 Oct/Nov 2025